CreateInputsModel: wrong area of sub-basin with upstream Reservoir, Lag or Direct Injection nodes

If a sub-basin has an upstream node with a model running with area=NA, then the area of the sub-basin is miscalculated because it doesn't take into account the area of the basins upstream the node with area=NA.

Solution: we need to look upstream the node in order to take into account the area of more upstream nodes.